CORNEAL TOPOGRAPHY CHARACTERISTICS OF MYO PIC CANDIDATES FOR REFRACTIVE SURGERY

Introduction Videokertography analyses the corneal anterior topography . It is necessary in refractive surgery to estimate the anatomical eff ect of surgery and to eliminate early Keratoconus. Methodology Corneal anterior topography was studied on 70 consecutive patients (140 eyes) candidates for low myopia surgery (-1 to -6); 87 eyes were wearing re gularly contact lenses. With the topographic analysis machine of EYESY S company, keratometry (Km) at 3 mm, astigmatism (Delta K) at 3 mm, I- S value at 3 mm and 5 mm according to Rabinowitz method were measured in each eye. Results The average keratometry was 43.50 +/- 1.87 D. The average astigmatism was 0,909 +/- 0.75 D. 51 eyes presented an asymme tric corneal and among them 32 ware contact lenses regularly; 8 eyes o ut of 140 (6%) presented the association of an high central Keratometr y value (greater than or equal to 47 D) and corneal asymmmetry (I-S > 0,5 value). Comments The incidence of Keratoconus is higher in a candi date population for refractive surgery by self-selection. Its frequenc y is difficult to evalute accurately because of the present limits for the diagnostic measures. In this population, it seems to represent ab out 6%. Conclusion The videokeratography before refractive surgery is necessary to reveal corneal anterior topography abnormalities and to e liminate early Keratoconus.